Vertical form/fill/seal (VFFS) packaging systems have proven to be very useful in packaging a wide variety of flowable or pumpable products. These products include such items as chocolate syrup, spaghetti sauce, mayonnaise, and other food products, and can include non-food products as well. An example of such a system is the Onpack pumpable food packaging system sold by W.R. Grace & Co.-Conn. through its Grace Packaging group. The VFFS process is known to those of skill in the art, and described for example in U.S. Pat. No. 4,589,247 (Tsuruta et al), incorporated herein by reference. A flowable or pumpable product is introduced through a central, vertical fill tube to a formed tubular film having been sealed transversely at its lower end, and longitudinally. The pouch is then completed by sealing the upper end of the tubular segment, and severing the pouch from the tubular film above it.
The choice of packaging materials is important, and should be matched to the intended end use of the pouch. For foods such as tomato-based sauces, for example, a laminate of relatively low oxygen transmission is usually required in order to provide extended shelf life for the product. The FS laminates, such as FS 6055B, also sold by W.R. Grace & Co.-Conn. through its Grace Packaging group, are examples of packaging materials suitable for the VFFS process. The FS 6055 B is a high oxygen barrier laminate that offers extended shelf life. It is also a material that is capable of, and in fact often used in commercial applications where the food product is hot filled, typically at 180.degree. F. to 200.degree. F., into the formed pouch during the VFFS process. Thus, this material offers the pumpable food processor both long shelf life and thermal stability for many hot-fill food items. These laminates are described in e.g. U.S. Pat. No. 4,746,562 (Fant), incorporated herein by reference.
An alternative laminate is based on Sclair (tm) sealant film, an ethylene/alpha-olefin copolymer marketed by DuPont Canada, and described in e.g. U.S. Pat. No. 4,521,437 (Storms), incorporated herein by reference. A commercial monolayer film from DuPont Canada is FS-3. A commercial multilayer laminate is CL 303.
Several ways of dispensing the contents of such pouches at their point of use have been proposed. One is the use of an internal fitment, such as the Asept (tm) fitment distributed in the U.S. by the assignee of the present application, and disclosed in U.S. Pat. No. 4,603,793 (Stern) incorporated herein by reference. In use, a coupling device would be inserted through the pouch material to communicate with the internal fitment, and a conventional dispensing device would be connected to the coupling device for delivering measured portions of the contents of the pouch.
An alternative technique and apparatus for dispensing the contents of a pouch is the use of a pouring spout such as the Top-Tap (tm) pouring spout supplied by DuPont Canada, and described in differing embodiments in their Canadian Patent No. 1,192,164 (Obidniak) and U.S. Pat. No. 5,325,995 (Harrison et al), both incorporated herein by reference.
This latter system generally involves piercing the filled pouch with the sharp end (piercing nozzle) of a pouring spout, and driving the piercing nozzle into the pouch interior until the laminate forming the pouch wall engages the shoulder of the piercing nozzle. When this occurs, the plastic material forming the pouch will dispose around the shoulder of the nozzle, to be secured by a collar. The pouring spout can then be used to dispense the contents of the pouch.
In some cases, a packager may wish to forgo the use of internal fitments such as those described earlier, and use a pouring spout such as that disclosed in the Obidniak and Harrison et al patents. This has proven practical when using materials such as the Sclair film. Unfortunately, however, when the package designer wishes to take advantage of the benefits described above for the FS laminates, in connection with these pouring spouts, a practical problem arises. The inventor has found that although the FS 6055 B material can be successfully pierced using e.g. the Top-Tap (tm) nozzles, when the material is brought up and around the shoulder of the nozzle device, and secured by the collar, the material pulls away somewhat from the device. This results in a relatively high rate of "leakers", i.e. pouches that leak. Although "leakers" can occur for a variety of reasons, the focus here is the leakage occurring in the vicinity of the shoulder of the piercing nozzle.
The inventor has found that this difficulty in making reliable packaging can be remedied, while still using the FS film in combination with a pouring spout. A lower incidence of leakers results.